The present invention relates generally to seat restraint systems for vehicles and, more particularly, to a tension sensing switch assembly for a seat restraint system in a vehicle.
It is known to provide a seat restraint system such as a seat belt in a vehicle to restrain an occupant in a seat of the vehicle. In some vehicles, the seat restraint system may be a lap belt, a shoulder belt or both. Typically, the lap belt and shoulder belt are connected together at one end. The seat restraint system includes a latch plate at the connected end. The seat restraint system also includes a buckle connected at one end by webbing or the like to vehicle structure. The buckle receives the latch plate to be buckled together. When the buckle and latch plate are buckled together, the seat restraint system restrains movement of the occupant to help protect the occupant during a collision.
Smart inflatable restraint systems need to know what is occupying a seat of the vehicle. Decisions on deployment on inflatable restraint depend on information supplied by sensors in the seat in determining weight of an object in the seat. When a child seat is placed in the seat and cinched down, the sensors may read a large mass instead of a child seat. With this condition, there will be high tension in the seat restraint system. Comfort studies have shown that no human occupant would wear their seat restraint that tight. With this information on seat restraint tension, the inflatable restraint system can decide on deployment of the inflatable restraint.
Although the above seat restraint system has worked, it is desirable to provide a switch for sensing tension in a seat restraint system of a vehicle. It is also desirable to provide a switch for a seat restraint system in a vehicle that allows a control module to determine the difference between either a child seat or a small occupant. It is further desirable to provide a switch for a seat restraint system in a vehicle that provides information used in determining inflatable restraint deployment levels.
It is, therefore, one object of the present invention to provide a switch assembly for sensing tension in a seat restraint system of a vehicle.
It is another object of the present invention to provide a dual resistance switch for sensing tension in a seat restraint system of a vehicle.
To achieve the foregoing objects, the present invention is a tension sensing switch assembly for a seat restraint system in a vehicle includes a housing for operative connection to the seat restraint system and a spring at least partially disposed in the housing for operatively cooperating with vehicle structure. The tension sensing switch assembly also includes a switch disposed in the housing and cooperable with the spring to indicate a first tension level and a second tension level in the seat restraint system when the spring is deflected.
One advantage of the present invention is that a tension sensing switch assembly is provided for a seat restraint system in a vehicle. Another advantage of the present invention is that the tension sensing switch assembly senses tension in the seat restraint system to help identify what is occupying the seat, either a child, child seat or low mass adult. Yet another advantage of the present invention is that the tension sensing switch assembly has a dual resistance switch that is diagnosable. Still another advantage of the present invention is that the tension sensing switch assembly provides information useful in determining deployment of an inflatable restraint system.
Other objects, features and advantages of the present invention will be readily appreciated, as the same becomes better understood after reading the subsequent description taken in conjunction with the accompanying drawings.